Five undefeated teams remain in the ACC through four weeks, and it's a safe bet that nobody expected Duke and Wake Forest to be among them.

Because, well, historically this is something that has never happened. For the first time, Duke and Wake Forest are 4-0 at the same time, joining Clemson, Virginia Tech and Miami without a loss.

Perhaps just as stunning: Florida State, the team chosen in the preseason to win the ACC, is the only winless team in the conference. That's right: Wake Forest is atop the Atlantic Division standings with Clemson, while Florida State is at the bottom with Boston College. Let that sink in for a minute.

Plenty has gone as expected through four weeks, but watching Duke and Wake Forest rise and Florida State fall qualifies as the biggest surprise.

Though No. 2 Clemson and No. 12 Virginia Tech played in the ACC title game last year, they have surprised, too, albeit in different ways.

Though both went into the season ranked, each team had questions to answer on offense: each lost its starting quarterback, best receiver and starting tight end. So far, Kelly Bryant at Clemson and Josh Jackson at Virginia Tech have drawn praise from their coaching staffs for their command and efficiency as first-time starting quarterbacks.

Virginia Tech offensive coordinator Brad Cornelsen said this about Jackson: "I think the thing that maybe separates him from … Jerod [Evans] from last year and the guys this year is he's got a chance to stand in the pocket and really get to where he's supposed to be going and make good decisions back there. It takes a little something extra, it takes some real savvy and understanding of what you're getting. He's got that in him."

Clemson's and Virginia Tech's defenses were expected to be good, but perhaps somewhat surprisingly, neither offense has slowed down that much with new players in new roles: Clemson and Virginia Tech remain in the top five in the ACC in scoring offense and total offense, near or above their averages from last year.

Clearly, the emergence of both Bryant and Jackson has helped, and College GameDay is going to Blacksburg, Virginia, on Saturday night for their highly anticipated Clemson-Virginia Tech matchup.

Florida State's early struggles have reset the pecking order in the ACC this season. Vasha Hunt//AL.com via AP

With Florida State out of the AP Top 25 for the first time since 2011, the Clemson-Virginia Tech game is filled not only with ACC championship ramifications but also with College Football Playoff ramifications. According to ESPN's Football Power Index, this is the most difficult game left on Clemson's schedule. Could the November date with Florida State end up being irrelevant now?

Currently, the FPI gives the Tigers and Hokies the inside edge at winning their respective divisions (72 percent for Clemson and 35 percent for Virginia Tech), and a 1-in-4 chance at playing a rematch in December in the ACC title game.

If Clemson wins, their chances of entering bowl season undefeated will rise from 21 percent to about 30 percent. That is a number to track as the ACC tries to make it back into the College Football Playoff.

As for Duke and Wake Forest, the road gets more difficult this weekend: The Blue Devils play host to No. 14 Miami and the Demon Deacons play host to the Seminoles. Duke and Wake Forest have gotten off to such good starts thanks to vast offensive improvement. They rank in the top five in the ACC in scoring offense after finishing in the bottom four last year.

Daniel Jones could be the best quarterback coach David Cutcliffe has had at Duke, and running back Brittain Brown has shown why the coaching staff believes in his vast potential. At Wake Forest, quarterback John Wolford has shown his own veteran leadership and the running game actually exists. In Year 1 under coach Dave Clawson, Wake Forest averaged 39.9 rushing yards per game. This year? It's 216.3 yards per game.

As for Florida State, the struggle has been real. Playing Alabama in the opener was not going to do anything for its offensive numbers. With quarterback Deondre Francois hurt, James Blackman played a solid game against NC State, but red zone problems had a major impact against another solid defensive front. Florida State is putting up un-Florida State-like numbers, averaging 72 yards rushing, 14 points and 316 yards per game -- all last in the ACC.

So the focus has shifted away from Tallahassee and to others in the ACC. In another month, there may be even more surprises in store.